Leveling is the positioning of a plane of an object perpendicular to the gravitational axis of the earth; whereas a plane is plumb when it is parallel to the earth's gravitational axis. For example, in a household setting, people typically prefer to level pictures, mirrors, and other framed objects so that these objects are parallel to the floor, ceiling and walls of a house, which are presumed to be level themselves. In a construction setting, numerous structural elements must be leveled to satisfy building codes and esthetic preferences. For example, as discussed above, leveling of framed objects requires that structures of a home be themselves level, which must be done during construction.
Positioning is the placement of an object, which may include its position in three dimensional space, or a rotational orientation. In some situations, positioning may include leveling. An example of positioning may include locating an object a certain distance from another object, orienting an object toward a compass point, locating the object a certain distance from sea level or ground level, and the like.
Various devices and methods can be used to level or position an object. One exemplary leveling device is a bubble or spirit level, which is a transparent and slightly curved vial that is incompletely filled with liquid. The resultant bubble in this vial settles to the center of the vial, when the vial is level.
While this is a typical device used to level or plumb objects, it is deficient because a user must be able to see the position of the bubble in order to properly use the instrument, and being at a distance, at certain angles, and having an obstructed view makes bubble levels unusable. Unfortunately, this substantially limits the use of such a device in many settings.
Additionally, in situations where a plurality of users is leveling an object, using a bubble level device can be cumbersome because at least one user must read the level and relay instructions to others. This is not efficient when an object is heavy or when it is not easy for users to view the bubble level while working.